WS2811. Signal line 256 Gray level 3 channal Constant current LED drive IC. Feature. Applications. General description

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1 Feature Output port compression 12V. uilt in stabilivolt, Only add a resistance to IC VDD feet when under 24V power supply. ray level 256 can be adjusted and scan freque ncy not less than 400Hz/s. uilt in signal reshaping circuit,after wave reshaping to the next driver, ensure wave-form distortion not accumulate. uilt-in electric reset circuit and power lost reset circuit. Cascading port transmission signal by single line. Any two point the distance more than 10m transmission signal without any increasecircuit. When the refresh rate is 30fps, low speedmodelc ascade number are not less than 512 points, high speed mode not less than1024 points. Send data at speeds of up to 400 Kbps and 800 Kbps two patterns. Applications LED decorative lighting. Indoor/outdoor LED video or irregular screen. eneral description The is 3 output channels special for LED driver circuit. It internal include intelligent digital port data latch and signal reshaping amplification drive circuit.also include a precision internal oscillator and a 12V voltage programmable constant current output drive. In the purpose of reduce power supply ripple, the 3 output channels designed to delay turn-on function. IC use single NZ communication mode.after the chip power-on reset, the port receivedata from con troller, the first IC collect initial 24bit data then sent to the internal data latch, theother data which reshaping by the internal signal reshaping amplification circuit sent to the next cascade IC through the port. After transmission for each chip,the signal to reduce 24bit. IC adopt auto reshaping transmit technology, making the chip cascade number is not limited the signal transmission, only depend on the speed of signal transmission. The data latch of IC depend on the received 24bit data produce different duty ratio signal at OUT, OUT, OUT port. All chip synchronous send the received data to each segment when the port input a reset signal. It will receive new data again After the reset signal finished. efore a new reset signal received, the control signal of OUT,OUT, OUT port unchanged. IC sent PWM data that received justly to OUT, OUT, OUT port, after receive a low voltage reset signal the time retain over 50us. We offer two package SOP8 and DIP8.

2 PIN configuration PIN function NO. Symbol Function description 1 OUT Output of ed PWM control 2 OUT Output of reen PWM control 3 OUT Output of lue PWM control 4 round 5 UT Data signal cascade output 6 Data signal input 7 SET Absolute Maximum atings Set work mode of IC as low speed model(connect VDD) or high speed model(vacant) 8 VDD Power supply voltage Prameter Symbol atings Unit Power supply voltage V DD +6.0~+7.0 V Output voltage V OUT 12 V Input voltage V I -0.5~VDD+0.5 V Operation junction temperature Topt -25~+85 Storage temperature range Tstg -55~+150 Note: If the voltage on the pins exceeds the maximum ratings may cause permanent damage to the device.

3 Electrical Characteristics(T A =-20~+70,V DD =4.5~5.5V,V SS =0V,unless otherwise specified) Prameter Smybol conditions Min Tpy Max Unit Low voltage I OL OUT 18.5 ma output current I dout Vo=0.4V,D OUT 10 ma Input current I I V I =V DD /V SS ±1 µa Input voltage level V IH D IN,SET 0.7V DD V V IL D IN,SET 0.3 V DD V Hysteresis voltage V H D IN,SET 0.35 V Switching characteristics(t A =-20~+70,V DD =4.5~5.5V,V SS =0V,unless otherwise specified) Prameter Symbol Condition Min Tpy Max Unit Operation Fosc1 400 KHz frequency Fosc2 800 KHz Transmission delay time t PLZ CL=15pF, UT,L=10KΩ 300 ns Fall time Data transmission rate t THZ CL=300pF,OUT/ OUT/OUT 120 µs F MAX Duty ratio50% 400 Kbps Input capcity C I 15 pf Low Speed mode time T0H 0 code,high voltage time 0.5 µs ±150ns T1H 1 code,high voltage time 1.2 µs ±150ns T0L 0 code,low voltage time 2.0 µs ±150ns T1L 1 code,low voltage time 1.3 µs ±150ns ES low voltage time Above 50µs Note: It is one half of the time when high speed mode(reset time unchanged)

4 Sequence chart: 0 code T0H 1 code T1H T0L T1L D1 D2 D3 D4 IC 1 IC 2 IC 3 ET code Treset Cascade method: reset code >=50us reset code Data refresh cycle 1 Data refresh cycle 2 D1 first 24bit second 24bit first 24bit second 24bit D2 second 24bit second 24bit D3 D4 Data transmission method: Note: The data of D1 is send by MCU,and D2, D3, D4 through IC internal reshaping amplification to transmit. Composition of 24bit data: Note: Follow the order of to sent data and the high bit sent at first.

5 Typical application circuit: 1.power supply is 5V with 1 LED and constant current (18.5mA) driving 5V 5V depend on controller LED controller VCC DAT VDD OUT OUT OUT VDD OUT OUT OUT Fig 1 This driving mode use constant current output, the advantage of is the LED can retain luminance and colour temperature when the power supply lessen. We require, in order to prevent power spikes phenomenon and power reverse polarity, series a not more than 100ohm resistor at the po-wer supply pin(vdd). The capacitance as bypass capacitor. To prevent the reflection and hot-swap protection, we suggest to connect a 33 ohm resistor at the data input or output port for impedance. 2.power supply is 12V with 3 LED and constant current(18.5ma) driving 12V 12V depend on controller 1 1 VCC LED controller DAT VDD OUT OUT OUT VDD OUT OUT OUT Fig 2 The same as the front mode, it is also use constant current output. In this circuit, 1 is used as the IC internal L divider resistance and the value is 2.7K. The capacitance as bypass capacitor. To prevent the reflection and hot-swap protection, we suggest to connect a 33ohm resistor at the data input or output port for impedance. At the OUT port we should add a divider resistance. The value of can be derived the following equation: 12-3V LED = KΩ 18.5 V LED is the red LED forward conduction voltage drop. by

6 3.power supply 12V with 3 LED and constant voltage driving 12V 12V 1 1 L L L L L L depend on controller VCC LED controller DAT DI N VDD OUT OUT OUT VDD OUT OUT OUT Fig 3 Applying the outside-enlarged transistor mode, the highest voltage value of VCC depends on the NPN transistor's V CEO, generally 25V above. The current of each channel is set by resistance //, computation formula is as follows: I = V CC -3V LED In above formula, I is the current of output end OUT, is the value of red voltage-dividing resistor, VCC as the power supply voltage of LED(here is 12V), V LED is the red LED forward conduction voltage drop, VCE as be set. the saturated pipe pressure drop of transistor. Likewise, the current of OUT and OUT can Select 5KΩ as value of base resistance L, magnification of NPN transistor β>150, connect circuit according to the method of Fig 3, the luminance data of MCU sends is opposite to actual luminance. 1 is L voltage-dividing resistor inside IC (1=2.7KΩ), the capacitance as bypass capacitors, input end and output end of IC are connected a resistance 33ohm in series respectively to provide hot-swap protection and resistance matching. - V CE

7 4.power supply 12V with 6 LED and constant voltage driving 24V 24V 1 1 L L L L L L depend on controller VCC LED controller DAT VDD OUT OUT OUT DI N VDD OUT OUT OUT Applying the outside-enlarged transistor mode, the highest voltage value of VCC depends on the NPN transistor's V CEO, generally 25V above. The current of each channel is set by resistance //, computation formula is as follows: I = V CC -6V LED In above formula, I is the current of output end OUT, is the value of red voltage-dividing resistor, VCC as the power supply voltage of LED(here is 24V), V LED is the red LED forward conduction voltage drop, VCE as the saturated pipe pressure drop of transistor. Likewise, the current of OUT and OUT can be set. Select 5KΩ as value of base resistance L, magnification of NPN transistor β>150, connect circuit according to the method of Fig 3, the luminance data of MCU sends is opposite to actual luminance. 1 is L voltage-dividing resistor inside IC (1=6.8KΩ), the capacitance as bypass capacitors, input end and output end of IC are connected a resistance 33ohm in series respectively to provide hot-swap protection and resistance matching. - V CE

8 Package imformation: DIP-8 Package: Symbo Dimensions In Millmeters Dimensions In Inches l Min Nom Max Min Nom Max A A A C D E E e L θ 0º 15º 0º 15º

9 SOP-8 Package: Symbol Dimensions In Millmeters Dimensions In Inches Min Max Min Max A A A b c D E E e L θ 0º 8º 0º 8º